The government's proposed expansion of "closed material procedures" (CMPs) into civil courts is an attempt to prevent sensitive claims for damages being aired in open hearings.

The move follows the embarrassing torrent of actions brought against the intelligence agencies by former terrorist suspects such as Binyam Mohamed, a British citizen held in Guantánamo Bay, who claimed he was tortured while detained in jails, including in US custody.

Under the proposals, not only would ministers be able to order a hearing to be conducted in secret, but the proceedings would also deny claimants access to government evidence or witnesses – leaving them effectively untested in court. In addition, the final judgment could be wholly or partially withheld.

The controversial reform is supported by senior figures in the security community, notably Sir Malcolm Rifkind, chairman of the parliamentary intelligence and security committee.

In his published submission, he argues that co-operation with foreign intelligence agencies such as the CIA will be endangered if secrets are exposed in court.

"It is essential that our courts are able to handle intelligence material, and that that material is properly protected," Rifkind states. "It is a fundamental principle of intelligence-sharing that such exchanges are kept confidential.

"Publication of other countries' intelligence material, whether sensitive or otherwise, undermines the key principle of confidentiality on which relations with foreign intelligence services are based and has the potential to cause serious harm to future intelligence co-operation and thereby undermine the national security of the UK."

Rifkind calls for additional protections, noting that "we do not consider that [secret courts] offer sufficient surety to our allies", and suggests adopting a US-style "executive veto" on release of intelligence material – although he admits such powers might not be compatible with the European convention on human rights.

Lord Carlile, the former independent reviewer of terrorism legislation, also expresses support for CMPs, "where it is necessary for the fair and balanced disposal of the case including national security issues".

The Serious Organised Crime Agency (Soca) also backs the development but says they should only be used "in exceptional cases where a fair trial would be impossible if a party were unable to rely on the sensitive material to defend a claim against it".

But a majority of the published responses are highly critical. Northamptonshire police's submission states: "It is proposed that CMPs are available whenever the secretary of state makes the decision that the disclosure of sensitive material will be damaging to the public. This is very widely drafted and could result in its misuse. This could be used to encompass material concerning crime prevention tactics, police informants and intelligence led operations.

"The impact of the overuse of CMPs would be to damage the UK reputation of a free and fair democracy."

The Northamptonshire force also questions whether they are consistent with article 6 of the European convention on human rights –the right to a fair trial. The force's chief constable is spokesperson on ethics for the Association of Chief Police Officers (Acpo).

The Equality and Human Rights Commission is damning in its rejection. "Closed material procedures are inherently unfair to the excluded party," their response says. "The right to know the evidence given by the other side is such a fundamental principle of natural justice, it can never be fairer to adopt a closed material procedure in order to determine a claim, even if the alternative is that the claim will be struck out."

John Hemmings, the Liberal Democrat MP who has challenged privacy hearings in parliament, observes: "There is very clear evidence that secret hearings are unreliable. This is obvious from the many false allegations of blackmail that have been made in recent privacy injunctions … When there is secrecy there is the potential for a disconnect between the judicial proceedings and reality."

The Police Service of Northern Ireland expressed concern about the integrity of inquests in Northern Ireland, particularly in historical cases from the Troubles, where coroners currently dispenses justice based on a "full consideration of the facts, sensitive or otherwise".

Among other organisations that have submitted critical responses are Amnesty International, the Committee on the Administration of Justice, Justice and the Guardian.

Acpo's submission enters a final plea: "There may be potential for confusion regarding the use of abbreviation CMP for 'closed material procedures' with the long established use of that abbreviation in the covert world for 'covert monitoring post/s'". So that surveillance secret is now out.